1. Field of the Invention
The invention relates generally to containers and, more particularly, to cans ends. The invention also relates to methods of making can ends.
2. Background Information
Many metallic containers for holding products (e.g., without limitation, food; beverages) are sometimes provided with an easy open end, wherein a pull tab is attached to a tear strip or panel that is defined by a scoreline. The pull tab may be lifted and then pulled to provide an opening for dispensing the contents of the container.
FIGS. 1 and 2 illustrate a conventional can end 1 as disclosed, for example, in U.S. Pat. No. 5,038,956. The can end 1 includes a recessed panel 3 defined by a generally vertical chuckwall 5, which surrounds the periphery of the panel 3. FIG. 1 shows the exterior (i.e., public) side 7 of the can end 1, whereas FIG. 2 shows the interior (i.e., product) side 9. A peripheral scoreline 11 (FIG. 1), which is disposed at or about the base of the chuckwall 5, defines an opening section 13 that is intended to be drawn away or removed from the can end 1 to provide access to the contents of the container (e.g., can) (not shown) to which it is attached. To facilitate rupture of the peripheral scoreline 11, an opening mechanism such as, for example, the pull tab 15 shown in FIG. 1, is coupled to the panel 3. More specifically, the pull tab 15 is typically riveted to the opening section 13 of the panel 3 by a rivet 17. A finger well 19 is sometimes included to enable the end user to reach beneath the pull tab 15 to initiate rotation thereof.
As shown in FIG. 2, in an effort to enhance the openability of the can end 1, some can ends 1 include a back scoreline 21 disposed inboard (i.e., toward the center of the can end 1) of the rivet 17 on the product side 9 of the can end 1. The back scoreline 21 is structured to facilitate initial rupture of the peripheral scoreline 11 (FIG. 1) that defines the opening section 13, and to avoid the pull tab 15 (FIG. 1) being accidentally torn off of the panel 3 during the can opening process. The back scoreline 21 of FIG. 2 is arch-shaped and includes an arcuate portion 23 and two substantially straight legs 25,27 extending outwardly away from the arcuate portion 23 toward a safety fold 29 that is contiguous with the base of the chuckwall 5. Thus, it will be appreciated that the can end 1 is a “panel safe” can end 1, meaning that the peripheral safety fold 29 remains with the panel 3, and is structured to shield any raw-edge residual metal remaining with the panel 3 when it is removed from the can end 1.
Scorelines, such as the arch-shaped back scoreline 21 of FIG. 2, suffer from a number of disadvantages. Among them is the fact that the arcuate portion 23 of the back scoreline 21 is disposed inboard of the rivet 17 a relatively significant distance 31 (e.g., at least about 0.03 inches). The position and geometry of the scoreline (e.g., 21) directly affect the opening mechanics of the can end 1. Additionally, as shown in FIG. 2, the example back scoreline 21 is disposed on the product side 9 of the panel 3. This increases the possibility of contamination of the product, for example, due to corrosion or oxidation of the scoreline 21. At a minimum, when using a relatively rigid container material (e.g., without limitation, steel) that oxidizes, the product side back scoreline 21 mandates a post score coating protection operation to coat the product side 9 of the panel 3 and, in particular, the back scoreline 21 thereof, in order to resist oxidation.
There is, therefore, room for improvement in can ends, and in methods of making can ends.